Showing papers in "Caryologia in 1976"
TL;DR: In Gentiana acaulis, where the anthers are elongated and mature in a scalar way, the tapetal cells are intermingled with pollen grains and possess simultaneously spherical cytoplasmic bodies, sporopollenin bodies and grey bodies.
Abstract: SUMMARYIn Gentiana acaulis, where the anthers are elongated and mature in a scalar way. the tapetal cells are intermingled with pollen grains and possess simultaneously spherical cytoplasmic bodies, sporopollenin bodies (« orbicular bodies ») and grey bodies. The contemporaneous presence of such bodies is probably related to the fact that the cell walls of the tapetal cells disappear and therefore they can migrate towards anther zones which are already mature.
28 citations
TL;DR: The erytrocytes of the three species of Acipenseridae show a strenght correlation between the size of the nucleus and the amount of DNA, and the nucleocytoplasmic ratio increase with the nuclear DNA content even if less than the nuclear areas.
Abstract: SUMMARYThe comparative DNA values, the nuclear size and the nucleocytoplasmic ratio were determined in three species of Italian sturgeons: Huso huso L. Acipenser sturio L. and Acipenser naccarii Bonaparte.The Acipenseridae have a very high nuclear DNA values: H. huso has 3,60 pgramms/nucleus, A. sturio 3,58 pgramms/nucleus. A. naccarii has 6,26 pgramms/nucleus is thus the highest within the range of DNA/nucleus values of the sturgeons, therefore this species can be regarded as a tetraploid.The erytrocytes of the three species of Acipenseridae show a strenght correlation between the size of the nucleus and the amount of DNA. The nucleocytoplasmic ratio increase with the nuclear DNA content even if less than the nuclear areas. The highest value is of A. naccarii with a less cytoplasmatic area.
28 citations
TL;DR: Anther sections of Antirrhinum maius in various stages of development have been examined with the electron microscope and the ultrastructural modifications of the tapetal cells have been followed during the development of the pollen grains.
Abstract: SUMMARYAnther sections of Antirrhinum maius in various stages of development have been examined with the electron microscope and the ultrastructural modifications of the tapetal cells have been followed during the development of the pollen grains. Characteristic of the early stages of development is the presence of a great number of intensely proliferating Golgi bodies and of spherical bodies, located in the perinuclear space in proximity of the plasmalemma and in the endoplasmic reticulum. They are bounded by a single membrane on which ribosomes are regularly ranged facing the body cavity. Probably the bodies located in the perinuclear space play a role in the nuclear-cytoplasmic information exchanges, while those in connection with the endoplasmic reticulum seem to be simply related to an enhanced endoplasmic reticulum activity. In the late tetrad stage a second body population appears. These bodies are spherical, electrondense and without bounding membrane. They are located at the cell periphery toward...
24 citations
TL;DR: Results suggest new techniques for study of the synaptonemal complex, chromosome structure, crossing over, chiasmate associations and other meiotic phenomena.
Abstract: SUMMARYChromosomes of maize microsporocytes exposed to ethanol have been found to exhibit an array of abnormalities: pachytene desynapsis, decondensation at later meiotic prophase and metaphase I, chiasmatic failure following crossing over, bivalent interlocking and polyspory. Results suggest new techniques for study of the synaptonemal complex, chromosome structure, crossing over, chiasmate associations and other meiotic phenomena.
19 citations
TL;DR: Different vegetative and floral parts of this naturally occurring triploid male plant of Momordica dioica were found to be intermediate between diploids and natural tetraploids.
Abstract: SUMMARYCytomorphological studies have been carried out in a naturally occurring triploid male plant of Momordica dioica. Different vegetative and floral parts of these triploids were found to be intermediate between diploids and natural tetraploids. Meiosis was highly irregular, forming trivalente and univalents. Pollen fertility was very low (about 2%). This triploid has been used in crossing experiments from which some fruits and seeds have been obtained.
18 citations
TL;DR: The estimated DNA contents of nuclei in the zygotes and 2-celled proembryos were within, or close to, the expected 2C-4C range.
Abstract: SUMMARYThe nuclear DNA content of Feulgen stained zygotes and young proembryo cells was investigated by microdensitometry in three barley genotypes. Apart from a few abnormally low estimates for nuclei in newly fertilized egg cells (caused by failure of the staining reaction), the estimated DNA contents of nuclei in the zygotes and 2-celled proembryos were within, or close to, the expected 2C-4C range. The present result differ from those for ‘Hannchen’ barley in which it was claimed (MERICLE and MERICLE 1970) that the nuclear DNA content of zygotes was as high as 16C and minimally 8C, but agree with WOODWARD'S (1956) results for Tradescantia.
15 citations
TL;DR: The karyotypes of six species of the genus Nigella could be investigated with somewhat modified C-banding techniques, and it allowed to establish some cytotaxoncmical relationships between the species.
Abstract: SUMMARYThe karyotypes of six species of the genus Nigella could be investigated with somewhat modified C-banding techniques, and in the case of N. damascena quantitative measurements of the C-bands could be performed.The C-banding patterns were analysed and found to occur at primary and secondary constrictions and at intercalary segments. It allowed to establish some cytotaxoncmical relationships between the species.
14 citations
TL;DR: The sexual Z chromosome is quite uniform, but W shows an appreciable variation in size and centromere position, thus pointing out different steps in the differentiation of this chromosome within the family.
Abstract: SUMMARYThe karyotypes of the following species of Brazilian Columbiformes (family Columbidae) were analysed: Claravis pretiosa, Columba cayennensis, Columba picazuro, Columba speciosa, Columbina picui, Columbina talpacoti, Geotrygon montana, Leptotila rufaxilla, Leptotila verreauxi, Scardafella squammata and Zenaida auriculata.The diploid chromosome number varied from 74 to 86. Great similarities were found among species belonging to the same genera, as in Columba, Leptotila, but Columbina species were quite different one from another, as far as karyotypes are concerned. Striking differences were found among genera. Structural rearrangements involving mainly centric fusions and fissions, as well as pericentric inversions, must have been responsible for the divergences observed. The sexual Z chromosome is quite uniform, but W shows an appreciable variation in size and centromere position, thus pointing out different steps in the differentiation of this chromosome within the family.
14 citations
TL;DR: Mitotic and meiotic chromosomes were studied in an Asian caecilian, Ichthyophis orthoplicatus, by a blood culture method and by spermatocyte squashes, and showed that the nucleolus organizer is on chromosome No. 3.
Abstract: SUMMARYMitotic and meiotic chromosomes were studied in an Asian caecilian, Ichthyophis orthoplicatus, by a blood culture method and by spermatocyte squashes. For this species, 2N=42, which is the highest chromosome number in the Order Gymnophiona. The karyotype consists of two large metacentrics, one medium-sized submetacentric, three medium-sized metacentrics, two small metacentrics, one small submetacentric, one small subtelocentric, and eleven telocentric microchromosomes. No heteromorphic pair of sex chromosomes is present in either sex. The 21 spermatocyte bivalents have a variable number of chiasmata, positively correlated with chromosome length. The largest bivalent frequently has four or five chiasmata. There are no ring-shaped bivalents. Observations of pachytene bivalents showed a heteropycnotic rod on the end of one arm of bivalent No. 1, and showed that the nucleolus organizer is on chromosome No. 3.If current concepts of caecilian systematics are correct, then primitive caecilians have high n...
14 citations
TL;DR: In the monogenic male sterile line LC-1 of H. annuus, an analysis on the development of meiosis was performed resulting in a rather frequent occurrence of multivalent associations at diakinesis and the first metaphase.
Abstract: SUMMARYThe present cytogenetic investigations that were carried out have established the karyotypes for the species Helianthus annuus L., variety Record (2 n=34) and for the species H. debilis Nutt. line 403 (2 n=34). The karyotype of H. debilis is of asymmetrical type, containing 3 groups of chromosomes, according to the new nomenclature of LEVAN et al. (1964). namely:The first group of metacentric chromosomes (10 pairs).The second group of submetacentric chromosomes with satellites (3 pairs).The third group of subtelocentric chromosomes (4 pairs).In the monogenic male sterile line LC-1 of H. annuus, an analysis on the development of meiosis was performed resulting in a rather frequent occurrence of multivalent associations at diakinesis and the first metaphase.
12 citations
TL;DR: The possibility of the evolution of the chromosome formula in different geographical cytotypes of P pipistrellus is discussed.
Abstract: SUMMARYExamination was made of the chromosomes of Common Pipistrelle and Nathusius' Pipistrelle originating from the Bialowieza Primeval Forest (52°42'N, 23°51'E). Identical 2N=44 and NFa=50 were found in both specics. The karyotypes of the species examined differ only in respect of the dimensions of one pair of marker chromosomes. The possibility of the evolution of the chromosome formula in different geographical cytotypes of P pipistrellus is discussed.
TL;DR: Cytological studies of Saccharum- Sorghum hybrid derivatives suggest that interaction between their genomes can take place and that different combinations of sugarcane and sorghum chromosomes are retained in different BC4 individuals.
Abstract: SUMMARYThe intergeneric hybrid between sugarcane (Saccharum officinarum L.) and sorghum (Sorghum bicolor (L.) Moench) was produced by pollinating sugarcane inflorescences with sorghum pollen. The BC4 population, produced by backcrossing twice with diploid (2 n=20) and then twice with tetraploid (2 n=40) sorgo, probably combined 40 Sorghum and 4–10 Saccharum chromosomes. The cytological observations suggest that different combinations of sugarcane and sorghum chromosomes are retained in different BC4 individuals. The sugarcane chromosomes either associate loosely with sorghum bivalents and/or tetravalents or pair autosyndetically. The sorghum chromosomes do not behave as in normal sorghum in the presence of sugarcane chromosomes and cytoplasm. Cytological studies of Saccharum- Sorghum hybrid derivatives suggest that interaction between their genomes can take place. Selling of these BG plants results in almost complete elimination of Saccharum chromosomes, and morphologically and cytologically modified tetr...
TL;DR: The ultrastructure of the tapetal cells was studied in Kalanchoe obtusa and Pelargonium zonale and the most characteristic feature was the presence of many spherical bodies bounded by a single membrane and containing cytoplasmic material.
Abstract: SUMMARYThe ultrastructure of the tapetal cells was studied in Kalanchoe obtusa and Pelargonium zonale. In an early stage of development the most characteristic feature was the presence of many spherical bodies bounded by a single membrane and containing cytoplasmic material. These bodies were localized in dilations of the ER and in the perinuclear space. In later stages, when the pollen was mature, the tapetal cells of Pelargonium contained many « grey » bodies and their plasmalemma was in close connection with the sculptures of the pollen grains.
TL;DR: This is the first report of the occurrence of polytene chromosomes in this genus and the chromosomes were most prominent in L. pedunculatus, a species with relatively larger chromosomes than the other two species examined.
Abstract: SUMMARYPolytene chromosomes have been observed in suspensor cells of three species of the legume Lotus [L. carmeli Boiss., L. pedunculatus Cav. and L. purshianus (Benth.) Clem. and Clem.]. The chromosomes were most prominent in L. pedunculatus, a species with relatively larger chromosomes than the other two species examined. This is the first report of the occurrence of polytene chromosomes in this genus.
TL;DR: The occurrence of high frequencies of multivalents in the amphidiploids in which on the basis of preferential pairing only bivalents are expected, indicates autosyndetic or intragenomic pairing between the chromosomes, indicating considerable segmental homology between some pairs of chromosomes of the two species.
Abstract: SUMMARYExperimental amphidiploids were induced by colchicine treatment of the F1 hybrids of Luffa acutangula x L. graveolens. These amphidiploids showed gigantism over the diploid F1 hybrids in all morphological features recorded, but fruit setting did not occur in spite of artificial pollination of the female flowers.Meiotic studies revealed the occurrence of univalents, bivalents, trivalents, quadrivalents and at times higher chromosome associations both at diakinesis and metaphase I. Consequently many irregularities were observed at anaphase I.The occurrence of high frequencies of multivalents in the amphidiploids in which on the basis of preferential pairing only bivalents are expected, indicates autosyndetic or intragenomic pairing between the chromosomes. This is an indication of considerable segmental homology between some pairs of chromosomes of the two species.Sterility in the amphidiploid may be partly chromosomal, due to univalents and multivalents, but mainly the sterility appears to be genic....
TL;DR: Le prime misurazioni delle quantita di DNA nucleare hanno inoltre indicato la presenza di cellule poliploidi negli epiteli intestinali ed una probabile correlazione tra quantita i DNA cromosomico e modalita evolutive.
Abstract: RIASSUNTOSulla base dei lavori piu recenti e stata avanzata l'ipotesi che nel phylum Echinodermata si presenti una enorme stabilita nel numero dei cromosomi. Le prime misurazioni delle quantita di DNA nucleare hanno inoltre indicato la presenza di cellule poliploidi negli epiteli intestinali ed una probabile correlazione tra quantita di DNA cromosomico e modalita evolutive. In particolare e stato osservato che specie piu evolute contengono una minore quantita di DNA ed ancora si ritrovano relativamente bassi valori di DNA cromosomico nelle classi Asteroidea, Echinoidea e Crinoidea che hanno sofferto una severa crisi permiana.
TL;DR: The nuclear DNA content of secretory trichome cells of Solanum nigrum has been studied by microspectrophotometry from initiation of the trichomes up to the fully differentiated and functioning organ.
Abstract: SUMMARYThe nuclear DNA content of secretory trichome cells of Solanum nigrum has been studied by microspectrophotometry from initiation of the trichome up to the fully differentiated and functioning organ. Some initials become 4C by endoreplication, while others remain 2C. All those which turn out to be secretory are with a 4C DNA content and, when become active, show a partial amplification of their genome. An endoreplication therefore occurs in all trichomes at a given stage of their differentiation.
TL;DR: This work construes the absorption process associated with the dynamic properties of the plasma-membrane macromolecular constituents in the dome-shaped cell and points out the ropheocytotic mechanism of the absorption.
Abstract: SUMMARYCarrying on the ultrastructural analysis of the sucking apparatus in Tillandsiae, this work construes the absorption process associated with the dynamic properties of the plasma-membrane macromolecular constituents in the dome-shaped cell.A ropheocytotic mechanism of the absorption is pointed out, supported by the presence of a great number of mitochondria, which does not differ substantially from DOLZMANN'S pinocytotic view. Also the presence of numerous active dictyosomes is made clear.
TL;DR: The comparative-karyologic analysis of the taxons showed some common features in their karyotypes, and using the karyological analysis is established the hybrid origin of the species Cricotopus silvestris.
Abstract: SUMMARYThe structure of the polytene chromosomes in the salivary gland of two hard for distinguishing species Cricotopus silvestris Fabricius and Cricotopus ornatus Meigen was studied. For the both salivary chromosomes mapes are worked out. Using the karyological analysis is established the hybrid origin of the species Cricotopus silvestris.The comparative-karyologic analysis of the taxons showed some common features in their karyotypes. There is some resemblance between II chromosomes of the species Cr. silvestris and III chromosomes of the species Cr. ornatus and between I chromosomes of Cr. silvestris and II chromosomes of Cr. ornatus. At the same time these species are well distinguished karyologically according to the number of chromosomes (the species Cr. silvestris has 2 n=4, but the species Cr. ornatus has 2 n=6) and the chromosomal polymorphism- Cr silvestris is more polymorphic. These date indicate the philogenetic jouth of the species Cr. silvestris.
TL;DR: The electron-dense zones visible in the mitochondria of the absorption apparatus found in Tillandsia usneoides, were considered to be aggregates of genetic material and macromolecules, in relation to the mitochondrial's synthetic capabilities connected to their growth and duplication.
Abstract: SUMMARYThe electron-dense zones visible in the mitochondria of the absorption apparatus found in Tillandsia usneoides, were considered to be aggregates of genetic material and macromolecules, in relation to the mitochondria's synthetic capabilities connected to their growth and duplication. Characteristic mitochondrial duplication by constriction were observed very frequently in connection with the typical absorption apparatus found in Tillandsiae.
TL;DR: When employing usual and unusual fixation procedures, all the components of the endomembrane system of the apical cells of Trichophyton mentagrophytes were detectable.
Abstract: SUMMARYWhen employing usual and unusual fixation procedures, all the components of the endomembrane system of the apical cells of Trichophyton mentagrophytes were detectable. The membranous structures having a direct continuity or a developmental interaction are the endoplasmic reticulum, nuclear envelope and cytoplasmic vesicles. Occasionally an intimate association between endoplasmic reticulum and plasmalemma was also demonstrated. The vesicles appear to be of two types: secretory vesicles, which are concentrated in the expanding apices; and provacuoles which inflate and fuse together, creating vacuoles. It is suggested that all the cytoplasmic vesicles may be included in the category of primary lysosomes.
TL;DR: The effects of colchicine on a colonial algal flagellate Gonium pectorale (Volvocales, Chlorophyceae) are recorded for the first time, with increases ranging from partial doubling, to diploidy and tetraploidsy, and increase in chromosome number being the outstanding effect.
Abstract: SUMMARYThe effects of colchicine on a colonial algal flagellate Gonium pectorale (Volvocales, Chlorophyceae) are recorded for the first time. While, lower concentrations up to 0.5% of colchicine do not produce any effects, 1.0% concentration of this alkaloid brings about contraction of chromosomes, accumulation of metaphase plates, polyploid nuclei, multinucleate cells and cell enlargement. At this concentration, increase in chromosome number is the outstanding effect, such increases ranging from partial doubling, to diploidy and tetraploidy. In none of the cases all the cells of colony seem to have been affected, since unaffected cells within the same colony showing normal chromosome number have been observed. The affected cells generally are observed not to divide further instead, they died.
TL;DR: It is concluded that at the concentration studied, 2,4-D did not produce more polyploids or anaphase anomalies than IAA or NAA, and kinetin interacted differentially with 2, 4-D and NAA.
Abstract: SUMMARYDuplicate callus cultures of Haplopappus gracilis (Nutt.) Gray were cultivated on agar B5 media containing 2 ppm 2,4-D or NAA with or without 0.1 ppm kinetin, or 2 ppm IAA with kinetin. The frequencies of polyploid cells and of anaphase anomalies were comparable in calli maintained on 2,4-D, NAA and NAA with kinetin, and in those cultured on 2,4-D and IAA with kinetin, which showed considerably higher frequencies of both than the other cultures. Kinetin interacted differentially with 2,4-D and NAA. It is concluded that at the concentration studied, 2,4-D did not produce more polyploids or anaphase anomalies than IAA or NAA.
TL;DR: Polytene chromosomes in different larval tissues of Urophora cardui L. and Atherix ibis Fbr.
Abstract: SUMMARYPolytene chromosomes in different larval tissues of Urophora cardui L. and of Atherix ibis Fbr. are described. Notes about the life history of these species are given.
TL;DR: Of the four chemicals, theobromine proved to be most potent mitotic inhibitor and brought about mitotic inhibition in all the algae investigated, to some extent or the other, levels of inhibition depending upon the concentrations of the chemicals or durations of treatment in the same concentrations.
Abstract: SUMMARYThe effects of four different chemicals (colchicine, MH, caffeine and theobromine) on four taxa belonging to Chara and Nitella have been studied cytologically. Out of four different chemicals, MH did not produce any immediate cytological effects, which however, appeared subsequently when the materials were transferred to chemical free medium subsequent to treatments. All the chemicals brought about mitotic inhibition in all the algae investigated, to some extent or the other, levels of inhibition depending upon the concentrations of the chemicals or durations of treatment in the same concentrations. Of the four chemicals, theobromine proved to be most potent mitotic inhibitor. Colchicine has induced polyploidy, even upto the level of tetraploidy in C. globularis and C. braunii. Cytokinetic inhibition was brought about rarely by colchicine in C. globularis and more frequently by caffeine and theobromine treatments resulting in binucleate cells. Pycnotic nuclei were observed in all the treatments of ...
TL;DR: Endoreduplicated cells appear in sub-cultures prepared by trypsinising cultures of Chinese Hamster in the plateau phase, which after a change of medium are grown for at least two days, in stoppered bottles.
Abstract: SUMMARYEndoreduplicated cells appear in sub-cultures prepared by trypsinising cultures of Chinese Hamster in the plateau phase, which after a change of medium are grown for at least two days, in stoppered bottles. E-cells perform the first DNA synthesis before trypsinisation and the second after it; therefore these cells were blocked or slowed down at the moment of trypsinisation in a stage of the cycle with 4C of DNA. This stage is probably comparable to a G. stage that follows a first cell cycle that has concluded without a normal mitosis.
TL;DR: The cytological investigation carried out on Helianthus nuttallii showed that, as a rule, the meiosis in PMC proceeds normally, and the frequency of disturbances recorded did not correlate with the degree of pollen viability and seed fertility.
Abstract: SUMMARYThe cytological investigation carried out on Helianthus nuttallii T. and G. showed that, as a rule, the meiosis in PMC proceeds normally. The frequency of disturbances recorded did not correlate with the degree of pollen viability and seed fertility.The karyotype of the species studied is characterized by four types of chromosomes: (A) two pairs with satellites; (B) seven pairs with medial to submedial centromere position; (C) five pairs with submedial centromeres, and (D) three pairs with subterminal centromeres. The chromosomes within the individual groups are very similar to each other wihch makes difficult their identification.
TL;DR: The maximum frequency of endoreduplicated cells occurs when the M-cultures are grown in bottles that have been stoppered also during the 6–9 days prior to the change of medium, so as to study the spontaneous appearance of cells with diplochromosomes in Chinese Hamster cultures.
Abstract: SUMMARYExperiments have been performed in order to study the spontaneous appearance of cells with diplochromosomes (endoreduplicated cells) in Chinese Hamster cultures. Endoreduplicated cells are present in sub-cultures (sub-M-cultures) prepared by trypsinising cultures (M cultures) in the plateau phase of growth. Two conditions are particularly important for the appearance of endoreduplicated cells: a change of medium 3 days before trypsinisation and the growth of the M-cultures in a closed atmosphere from that moment on. The maximum frequency of endoreduplicated cells occurs when the M-cultures are grown in bottles that have been stoppered also during the 6–9 days prior to the change of medium. In these conditions the frequency of endoreduplicated cells found in the sub-M-cultures 26–30 hours after trypsinisation varies around 8%. In the crowed M-cultures, which grow in closed atmospheres, the change of medium is followed by an unbalanced cell growth that leads to a greater protein content per cell. On ...
TL;DR: Present findings and previous records indicate that polyploidy is of frequent occurrence in this taxon.
Abstract: SUMMARYA cytological study on Ottelia alisnoides has been carried out in order to ascertain the existence of chromosomal biotypes in this taxon.Plant materials have been collected from different localities of West Bengal. A mixture of.002 M oxyquinoline solution and saturated aesculine solution (1: 1) has been most effective in pretreatment at 10–12°C for 3 hours. By performing usual aceto-orcein squash method, somatic chromosome numbers has been found to be 2 n=22, 2 n=44, 2 n=66, and 2 n=88 in plant materials of different localities. Karyotype studies of the plants reveal six different types of chromosomes. Somatic complements of different plant types as revealed from their idiograms show different combinations of six chromosome types.Present findings and previous records indicate that polyploidy is of frequent occurrence in this taxon. Present findings of 2 n = 22, 44 and 66 chromosomes tally with the reports of previous workers. The present observation of 2 n=88 chromosomes is new.
TL;DR: Most nuclei of the dormant first leaf of barley contain 2C level of DNA and a very small number however, have 4C DNA value while 0.9% appear to be intermediate between 2C and 4C.
Abstract: SUMMARYMost nuclei (97.9%) of the dormant first leaf of barley contain 2C level of DNA. A very small number (1.2%) however, have 4C DNA value while 0.9% appear to be intermediate between 2C and 4C. Nuclei initiate DNA synthesis after 12 h of germination and a cell population replicates the genome in partial synchrony as revealed by a peak in labelling index. Mitosis is initiated at 20 h and there is a peak in the mitotic index at 26 h. The interval between the initiation of DNA synthesis and mitosis in thus 8 h which is also the interval between the peak of labelling index and that of mitotic index.